230 DRY FARMK^G 



rye or barley and with better results. If these measures 

 do not result in more or less complete eradication, tame 

 grasses should be sown and left down two years or more, 

 and a year taken to break up the land before the next 

 crop is put in. 



The annual mustards and all other plants of similar 

 habit may be controlled by the practices outlined for 

 Wild Oats. Harrowing the growing crop after it is up, 

 a practice that will not kill Wild Oats, is an additional 

 means of killing the smaller seedlings of these annual 

 plants. On account of the long time the hard seeds of 

 many of these weeds may live in the soil, the use of 

 perennial crops has not proven as useful a means of 

 control as in the case of Wild Oats. 



180. The Control of Winter Annual and Biennial Weeds. 

 — Most of the so-called winter annuals, of which Tum- 

 bling Mustard and Stinkweed are typical examples, 

 may develop as annuals if they happen to get a start 

 early enough in the season. If they start in the spring 

 they may be prevented from seeding by the practices 

 suggested for controlling annual weeds. Those that 

 start in the fall and those of the earlier plants that 

 have not produced seed may be killed by the treatment 

 outlined in the next paragraph for biennials. 



Blue Burr and Tansy Mustard are typical biennial 

 weeds. If clean seed is always sown, and if seeds of 

 Tansy Mustard are kept from blowing in, and those of 

 Blue Burr from being carried in by stock or otherwise, 

 these weeds can be controlled by late fall or early spring 

 cultivation of all fields whether fallow or stubble. Fall 

 or spring plowing of stubble fields is to be preferred. 

 Disking will kill the young plants only if the discs are 

 sharp and the soil firm. Thorough cultivation of the 



